The present invention relates to an anterior chamber ocular implant for treating conditions of the phakic eye, in particular myopia, astigmatism and hypermetropia.
Such an implant consists, in a known manner, of an optical part (lens), generally of circular contour and with a section appropriate for the planned correction (plane, planoconvex, biconvex, planoconcave, biconcave, meniscus, toric); connected to this optical part there is a haptic part which is intended to fix the position of the optical part in the anterior chamber. The haptic part consists of fine and deformable loops which, in use, lodge in the iridocorneal angle.
An implant of the above type, intended for correction of myopia, is shown diagrammatically in FIGS. 1, 2 and 5 appended to the present description, FIG. 1 being a plan view, FIG. 2 a side view, and FIG. 5 a diagrammatic view of the implant according to FIGS. 1 and 2 in position in an eye.
FIG. 1 shows the optical part 1, the connection zone 2 between this optical part and the two loops 3 and 4 which have the general shape of an S, the distal part of each loop having two support feet 5 and 6.
It will be seen in FIG. 2 that the optical part 1 is of the concave type and that the loops 3, 4 are angulated from their proximal part for connection with the optical part 1 towards their distal support part, relative to a vertical support plane A.
This angle xcex1 is of the order of 15xc2x0 and is intended to ensure that the optical part 1 is placed in the anterior chamber of the eye without risk of contact either with the cornea on its front face or with the iris on its rear face.
It will also be seen in FIG. 2 that the distal end of the loops 3 and 4 coincides with the vertical plane A along a relatively important length.
The implant has a width of about 5.5 mm (reference L in FIG. 1) and is inscribed in an envelope curve having a diameter of between 12 mm and 13.5 mm (reference D in FIG. 1). Such an implant is adapted to most shapes and sizes of eyes encountered in patients recovering from refractive surgery.
However, with the earlier models, irritation was found in a not inconsiderable number of cases due to the fact that the distal part of the loops bears on the periphery of the iris.